Electrode for discharge tubes



y ,1929. w. F. HENDRY ELECTRODE FOR DISCHARGE TUBES Filed Dec. 29, 1926WILLIAM F, HEZNPRT EJ S-(LQL Mic/1f)? Patented May 28, 19 29.

UNITED srA'rss IPATENTOFFICE.

WILLIAM F. HENDRY, or ossrnrne, NEW YORK, ASSIGNOR T0 MANHATTAN ELECTRI-I cAL SUPPLY ooMPAnY, INC., A CORPORATION or MASSACHUSETTS.

ELECTRODE FOR DISCHARGE TUBES.

' Application filed December 29, 1926. Serial No. 157,699.

This invention relates to tubes having internal electrodes and relatesmore particularly to a method and means whereby large electrodes may beplaced inside tubes through openings that are too small to pass a normalelectrode.

The object of my invention is to so construct an electrode that it maybereduced in size and hence be inserted inside a tube envelope throughan opening of smaller diameter than that of a normal electrode. I

-Certain types of discharge tubes, for example rectifiers, known to theart, are now provided with an electrode of a size so large that it isextremely difficult to construct a satisfactory tube cheaply andeficiently due to the difliculty of assembling the large electrodewithin the envelope. Certain of the tubes now in use have a narrowbottle neck with an enlarged body portion and it is to this type of tubewhich my invention more particularly applies.

The invention will be more readily understood by reference to theaccompanying drawing and description thereof which follows:

Figs. 1 to 6 of the drawing represent tubes having electrodesconstructed according to the invention. Figs. 1, 3 and 5 show theelectrodes as they appear when they are'inserted through the bottleneck, while Figs. 2, 4 and 6 are showings of the electrodes when mgunted in the operative position inside the tu e.

Fig. 1 of the drawings shows a tube having a normally hemisphericalelectrode made of a plurality of pieces and the pieces all overlappedand adjusted to the same position so that the electrode may be insertedthrough the narrow neck of the tube, then expanded to its normal sizeand riveted in shape as shown in Fig. 2.

through the bottle neck into the envelope and, then be unrolled andriveted in its final shape.

It is in many cases a marked advantage to have a very large electrodeinside a tube of small dimensions and now by an arrangement Y asillustrated above adischarge tube having a small neck opening in theenvelope may easily be made with a large internal electrode. In tubes ofthe prior art-the size ofthe electrode has been limited practically bythe sizeof the opening into the envelope. r

i I have illustrated three forms which my invention maytake but do notintend to be limited to the specific 'forms shown as other means ofcarrying outthe. invention will readily occur to one skilled in the art.

I desire to be limited only to the extent set forth in the appendedclaims.

What I claim is:

1. In an electrical discharge tube having a small opening through whicha large electrode must be inserted in assembling the tube,

an electrode inside the tube having a normal operating form in the shapeof a hollow cup too large to be insertedthrough' the opening in thetube, said electrode comprising a rotatable portion by virtue of whichthe size of the electrode may be reduced sufficiently to allow it topass through the opening in the said tube.

2. An electrical discharge tube comprising a hollow hemisphericalelectrode made in a plurality of sections interleavably mounted on acommon pivot'point and secured against relative movement.

3. An electrode for an electricaldischarge ,tube, comprising a pluralityof sections col lapsibly mounted on a common pivot whereby I V ofhemispherical electrode forming elements movably hinged to a commonpointwhereby the said electrode may be reduced in size, and having means formaintaining the said plu- .rality of portions in afixed positionrelative.

to .each other.

In testimony whereof, I have signed my name to this specification, this27th day of December, 1926.

WILLIAM F. HENDRY.

